Distributed process control systems, like those used in chemical, petroleum and/or other processes, systems, and/or process plants typically include one or more process controllers communicatively coupled to one or more field devices via any of a variety of analog, digital and/or combined analog/digital buses. In such systems and/or processes, field devices including, for example, valves, valve positioners, switches and/or transmitters (e.g., temperature, pressure, level and flow rate sensors), are located within the process environment and perform process control, alarm and/or management functions such as opening or closing valves, measuring process parameters, etc. Process controllers, which may also be located within the plant environment, receive signals indicative of process measurements made by the field devices and/or other information pertaining to the field devices. Based on, for example, the received signals, the process controllers execute a controller application to realize any number and/or type(s) of control modules, software modules, software sub-systems, routines and/or software threads to initiate alarms, make process control decisions, generate control signals, and/or coordinate with other control modules and/or function blocks performed by field devices, such as HART and Foundation Fieldbus devices. The control modules in the controller(s) send the control signals over the communication lines to the field devices to control the operation of the process plant.
Information from the field devices and/or the controller is usually made available over a data highway or communication network to one or more other hardware devices, such as operator workstations, personal computers, data historians, report generators, centralized databases, etc. Such devices are typically located in control rooms and/or other locations remotely situated relative to the harsher plant environment. These hardware devices, for example, run applications that enable an operator to perform any of a variety of functions with respect to the process(es) of a process plant, such as changing an operating state, changing settings of the process control routine(s), modifying the operation of the control modules within the process controllers and/or the field devices, viewing the current state of the process(es), viewing alarms generated by field devices and/or process controllers, simulating the operation of the process(es) for the purpose of training personnel and/or testing the process control software, keeping and/or updating a configuration database, etc.
As an example, the DeltaV™ digital automation system sold by Fisher-Rosemount Systems, Inc., an Emerson Process Management company, supports multiple applications stored within and/or executed by different devices located at potentially diverse locations within a process plant. A configuration application, which resides in and/or is executed by one or more operator workstations, enables users to create and/or change process control applications, and/or download process control applications via a data highway or communication network to dedicated distributed controllers. Typically, these control applications are made up of communicatively coupled and/or interconnected control modules, software modules, software sub-systems, routines, software threads and/or function blocks that perform functions within the control scheme (e.g., process control and/or alarm generation) based on received inputs and/or that provide outputs to other blocks within the control scheme. Each dedicated controller and, in some cases, field devices, stores and/or executes a control application that runs the control modules assigned to implement actual process control functionality.
The configuration application also allows a configuration engineer to create one or more displays (e.g., a viewing application), for use by operators, maintenance personnel, etc. of the process plant, by selecting and/or building display objects using, for example, a display creation application. An example viewing application displays data for a process plant operator and/or enables the operator to change settings, such as set points and/or operating states, with the process control routines. These displays are typically implemented on a system-wide basis via one or more of the workstations, and present preconfigured displays to the operator and/or maintenance persons regarding the operating state(s) of the control system(s) and/or the devices within the plant. Example displays take the form of alarming displays that receive and/or display alarms generated by controllers or devices within the process plant, control displays that indicate the operating state(s) of the controller(s) and other device(s) within the process plant, maintenance displays that indicate the functional state of the device(s) and/or equipment within the process plant, etc.